1. Field of the Invention
This invention relates to barricades and more particularly to barricades usable to warn drivers and pedestrians of dangers at construction sites and the like. The barricades of the invention are rugged, reliable and have a long service life. They include component parts that can serve a number of functions and be assembled in a many different ways to provide a variety of configurations including configurations that permit folding for compact storage and transport. Constructions and methods are provided by which the barricades can be economically manufactured and low in cost.
2. Background of the Prior Art
One type of barricade structure is a saw-horse structure in which two units are pivotally connected for movement between a folded condition against each other and an operative condition in inverted V-relation. In an early type of saw-horse structure, many of which are still in current use, each unit is in the form of a subassembly with wood panels secured to a pair of metal legs with bolts connecting the legs to form the pivotal connection.
Many saw-horse structures have been used or proposed using components molded from plastic. The Stehle et al. U.S. Pat. No. 3,880,406 issued Apr. 29, 1975 discloses a plastic barricade in which units are pivotally connected by bolts after being formed with integral panels and legs. The units are formed by rotational casting to be hollow and to be filled with sand or other ballast to resist tipping over.
The Sawyer U.S. Pat. No. 3,971,331 issued Jul. 27, 1976 discloses use of panels formed by plastic and secured to legs that are connected by bolts.
The Glass U.S. Pat. No. 4,298,186 issued Nov. 3, 1981 discloses a barricade including a pair of identical members of hollow plastic that provide integral panels and legs. The members have hinge sections located at upper corners thereof and configured to be connected together by bolts. At the lower ends, hollow sand bars are provided for receiving sand bags.
The Glass U.S. Pat. No. 4,624,210 issued Nov. 25, 1986 discloses a barricade similar to that of U.S. Pat. No. 4,298,186 but having a special detent for locking the structure in an operative condition.
The Kulp U.S. Pat. No. 4,859,983 issued Aug. 22, 1989 discloses a barricade which is similar to the saw-horse structures of the Glass and other prior patents in having a pair of members of plastic that have hinge portions connected by hinge pins and that provide integral panels and legs. The barricade is described as being of the A-frame type but is unlike the A-frame structures described herein which include beams or rails supported between two A-shaped members.
The Glass U.S. Pat. No. 4,974,815 issued Dec. 4, 1990 discloses a barricade including a pair of members of plastic that provide integral panels and legs. The members are connected by a hinge pin which extends through a handle member.
The Thurston U.S. Pat. No. 5,003,912 issued Apr. 2, 1991 discloses a plastic barricade which includes two identical integrally molded plastic panels connected by hinge pins. Each panel has protrusions and indentations which can interlock with those of adjacent panels when stacking the panels.
The Thurston U.S. Pat. No. 5,009,541 issued Apr. 23, 1991 discloses plastic barricade having hinges formed by a cylindrical male boss that can mate with on open C-type clamp of sufficient flexibility as to form a female socket that can be snapped onto the male boss. As described, different cross-sections may be used and all that is necessary is that no unwanted forces are applied to the relatively fragile plastic hinge.
The Thurston U.S. Pat. No. 5,046,885 issued Sep. 10, 1991 discloses a hinged barricade similar to that of his U.S. Pat. No. 5,009,541 but differing in that the C-shaped female socket is formed by compression molding an in that the male boss has diametrically opposed flattened sides for insertion into the socket. After insertion into the socket, a limiting bolt is installed to limit the relative angular displacement to 40 degrees.
The Bent et al. U.S. Pat. No. 5,458,434 issued Oct. 17, 1995 discloses a plastic barricade formed from identical panels and hinged together by bolts The panels include handles at the top and a bottom-most cross-member formed with a stacking lug that can fit into an opening of a handle of an adjacent folded barricade.
The Cushman U.S. Pat. No. 5,544,614 issued Aug. 13, 1996 discloses a barricade assembly including a plurality of panel units which can be secured together, one above another, to provide an adjustable height. The uppermost panels are connected by hinge bolts or pins.
The Glass et al. U.S. Pat. No. 5,570,972 issued Nov. 5, 1996 discloses a plastic traffic barricade formed by two panel units connected by hinge bolts, each panel having an integral handle arranged for mounting of a flasher light thereon.
The Glass et al. U.S. Pat. No. 6,101,967 issued Aug. 15, 2000 discloses a barricade formed by two units each including a pair of legs and a plurality of panels formed by blow-molding. The upper ends of the legs of each unit are connected by hinge bolts to the upper ends of the legs of the other unit. Each leg has an I-beamed shaped cross-section recesses with depressions in one flange thereof. Channels are formed in an inner face of each panel adjacent the opposite ends thereof to receive leg members while being seated in the depressions of the leg members.
The foregoing patents related to saw-horse structures. Another barricade structure, referred to herein as an A-frame structure, includes rails or beams which have ends supported by members which are A-shaped. The Parker U.S. Pat. No. 3,089,682 issued May 14, 1963 discloses a barricade including a one-piece top member which forms a rail or beam and which is supported by a pair of oppositely disposed A-shaped legs. The top member and legs are disclosed as being formed of resilient hard rubber.
The Thomson et al. U.S. Pat. No. 4,943,035 issued Jul. 24, 1990 discloses a barricade with A-shaped members supporting the ends of an elongated hollow crossbar which includes elongated hollow inter-connecting sections.
The Giannelli U.S. Pat. No. 5,762,444 issued Jun. 9, 1998 discloses an A-frame barricade capable of being adjusted to a desired length. A pair of A-frames are connected by a transverse beam assembly which includes a pair of members arranged for relative slidable movement to be of adjustable length. Each A-frame includes an opening for receiving an end of the beam assembly and also includes a cross brace portion with an integral bracket providing a second opening which can receive the end of an auxiliary cross-beam. The auxiliary cross-beam is not shown but can be used to support one of more sand bags.
The Bartlett U.S. Pat. No. 5,794,923 issued Aug. 18, 1998 discloses a dressage arena fence with brackets that are A-shaped with a pair of leg portions that extend downwardly and outwardly from an apex portion but with no cross brace. Slots are provided in the brackets for interlocking engagement with ends of rails. As shown, one slot is provided in one leg of a bracket while two slots are provided in the opposite leg of the bracket.
This invention was evolved with the general object of making barricades that will better serve the requirements of users, that will be rugged and reliable and have a long life and that can be economically manufactured.
Important aspects of the invention relate to the recognition of problems with prior art barricades and analyses of how to deal with those problem. One problem is that although the barricade configurations known in the art are suitable for many applications, there are many applications where different configurations would be desirable. One way to deal with this problem might be to simply modify known configurations to produce a number of configurations each suitable for a particular application. However, it is desirable that barricades be of plastic and providing the tooling required to produce a number of configurations could be prohibitively expensive.
One particular problem with prior saw-horse barricades of molded plastic is that each has a particular size and panel configuration which will not be ideal for many applications. Another particular problem with prior saw-horse barricades is that although their typical height of around forty inches is suitable for many applications, there are other applications in which a greater height would be desirable. For example, barricades are frequently used to warn drivers or pedestrians about excavations that may be one to two feet in depth. If a structure with a height of forty inches is placed in such an excavation, the upper end may not be sufficiently visible, and if placed outside such an excavation, the structure can be displaced to fall into the excavation. These problems might be avoided by providing higher structures that can be placed in a stable position in an excavation and have an upper end that is in a clearly visible position.
A-frame barricade structures have a similar height problem. Both types of structures have potential stability problem in that increasing the height without other changes will increase the likelihood that wind or other forces will overturn the barricade.
In accordance with important features of this invention, legs are provided that have the same configurations but can perform a variety of functions in both saw-horse and A-frame structures.
To provide saw-horse structures, a pair of the legs are connected by panels to form each of two subassemblies which are pivotally connected. The panels are of different heights and holes are provided in the panels and legs to allow for connection in different configurations, each suitable for a particular application.
The legs can also be used to increase height and stability of A-frame structures in which a pair of A-frames are provided each having two vertically spaced openings through which two beams extend to be supported by said A-frames. To increase height, each leg can provide three openings along its length and each is arranged to extend vertically along an A-frame with the lower two of the three openings of the leg in registry with two openings in the A-frame to receive and be supported by the two beams. With two legs so supported from two A-frames, the third of the three openings of the legs can receive and support the ends of a third beam at a higher elevation.
To increase stability of an A-frame structure, a pair of the legs can be connected to lower ends of the legs of the A-frames with each extending horizontally beyond the such lower ends of the legs and increase an effective horizontal base dimension of the structure. A pair of legs can be so used in a complementary fashion to compensate for a decrease in stability which might otherwise result from use of a pair of legs to increase height. However, one pair of legs can be used to increase stability of an A-frame structure without using a pair of the legs to increase height.
Important features relate to the provision of legs that can be of either a shorter size or a longer size to be usable to provide two different heights in saw-horse structures with the longer size being usable in A-frame structures to increase height and to increase stability. The legs are so configured that both sizes can be molded with similar configurations but with minimal tooling changes. The legs of either size are identical, facilitating low tooling costs and low manufacturing costs.
In accordance with specific features of the invention, each leg includes two spaced longitudinally extending flanges and a web extending between and connecting the flanges. Frangible portions are preferably provided in the web which can be hammered out to produce the opening desired for extending the height of A-frame structures but which can be left in place for strength and rigidity when used in saw-horse structures or for stability of A-frame structures. A series of holes is provided in one flange for mounting of a panel in engagement with edges of both flanges when used in a saw-horse type structure.
A very important feature of the invention relates to the provision of projecting portions on the one end of each leg which can engage like portions on an adjacent leg to provide a knuckle journaling the legs for relative movement about a pivot axis between a closed condition in side-by-side relation and an open condition in inverted-V relation. With this feature, the legs can be identical but a strong and highly reliable pivot connection can be provided without using any bolts or pivot pins.
In a preferred construction, projecting portions of each leg define a pair of internal bearing surfaces facing each other and a pivot axis and define a pair of external bearing surfaces facing in opposite directions away from said axis, the internal bearing surfaces of each leg being engageable with the external bearing surfaces. The relative diameters and axial lengths of said external and internal bearing surfaces are such as to develop high frictional forces opposing relative axial movement of subassemblies of which the legs form a part. A positive limit on such axial movement is provided by engagement of legs with upper portions of connecting panels which are deformable to facilitate assembly and disassembly but which are not likely to deform during use even under the normally rough handling expected at a construction site.
Another feature is that the projecting portions of each leg define stop surfaces that are engageable with said stop surfaces of the other leg to limit the relative pivotal movement. In addition, the legs are provided with hook portions which function to engage upper portions of panels to assist in limiting relative pivotal movement the subassemblies.
A further feature is that folded assemblies are flat and compact and can be can be stacked with other like assemblies for storage and transport. Each of the legs includes a projecting post at one end and a hole at the opposite end, each post being arranged to engage in a socket provided by a hole of a leg of another assembly for alignment when stacked. The same hole is usable for mounting of a warning light when the leg is used as a vertical post in an A-frame structure.
Still another feature relates to the construction of panels which are arranged to be mounted in predetermined positions on the legs and which include portions which mate with the legs to insure mounting in such predetermined positions during assembly.
Further important features relate to methods molding of the legs. Shorter legs are molded using a first set of tools for forming major portions of the lengths of the shorter legs and using a second set of tools of short length for forming only lower end portions of the shorter legs, Longer legs are molded the first set of tools for forming substantial portions of the lengths of the longer legs together with a third set of tools for forming intermediate portions of the longer legs and a fourth set of tools for forming lower leg portions of longer legs. The third set of tools have the same short length as said second set of tools to be interchangeable therewith. During a press run, the first and fourth sets of tools can be kept in place in a press at all times, changing between molding of short and long legs during the press run being effected by interchanging said second and third sets of tools.
To provide for use of longer legs as vertical posts of A-frame structures, a web portion of each leg is so molded through use of first set of tools as to produce two frangible web portions and is so molded through use of the fourth set of tools as to produce a third frangible web portion, such frangible web portions being so formed that they can be hammered out and removed to provide three beam openings along the length of longer legs. Such frangible web portions are also so formed as to provide added strength when left in place in either shorter or longer legs that are used in saw-horse type structures.
The invention thus provides legs and panels which can perform a wide variety of functions with a high degree of reliability but which can be molded from plastic with minimal tooling and at low costs.
This invention contemplates other objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings.